Red Hat Enterprise Linux is the leading platform for open source computing. It is sold by subscription, delivers continuous value and is certified by top enterprise hardware and software vendors. From the desktop to the datacenter, Enterprise Linux couples the innovation of open source technology and the stability of a true enterprise-class platform.
http://www.redhat.com/software/rhel/
Red Hat Enterprise Linux v.4 Features and Benefits
Red Hat Enterprise Linux v.4, released in February 2005, provides significant technology enhancements over the v.3 release. Areas of specific development include improvements in security capabilities, increased server performance and scalability, and enhanced desktop capabilitiesall while ensuring a high level of compatibility with prior releases. Red Hat Enterprise Linux supports a wide range hardware and software applications, and is the world's leading enterprise-focused Linux environment.
http://www.redhat.com/software/rhel/features/
